Electromagnetic centrifugal pump



Jan. 17, 1956 K. o, DONELIAN ETFAL 2,730,951

ELECTROMAGNETIC,CENTRIFUGAL PUMP Filed Jan. 20. 1950 2 sh et -s t 1 INVEN TORS I/Pafffil'k d arzelzazz BY @7172 K/Vezz/re N E L Jan. 17, 1956K. o. DONELIAN mm.

ELECTROMAGNETIC CENTRIFUGAL PUMP 2 Sheets-Sheet 2 Filed Jan. 20, 1950.@m// W Q a 2 a 1 Wm j j z a? w m mm w W L Z f 2 co 5, B

United States Patent ELECTROMAGNETIC CENTRIFUGAL PUMP Khatchik O.Donelian, Jackson Heights, and John R. Menke, Riverdale, N. Y.,assignors to the United States of America as represented by the UnitedStates Atomic Energy Commission Application January 20, 1950, Serial No.139,604

2 Claims. (Cl. 1031) This invention relates to electromagnetic pumps andmore particularly to an improvement in such pumps wherein a magneticfield revolves in a circular path, such as in pumps of the typedescribed in U. S. Patent 2,658,452 issued to K. O. Donelian on November10, 1953.

A device for pumping electrically conductive liquids, such as alloys ofsodium and potassium, by means of an electromagnetic centrifugal systemis disclosed in the above-mentioned copending application. In general,the liquid is whirled within a pump chamber by the interaction of arotating magnetic field and of the currents induced in the conductingliquid by the rotating field, causing the conducting liquid to followthe field in its circular path at a relatively high velocity and then tobe thrown outwardly by centrifugal force into an annular peripheralchamber from which the liquid exits through an outlet passage at theperiphery.

The pump forming the subject matter of the present invention is animprovement over previous electromagnetic pumps in that better use ismade of kinetic energy accumulated by the rotating liquid. This isaccomplished by the use of a flat disk-shaped chamber into which theelectrically conductive liquid enters at the center and is caused towhirl by the rotating magnetic field as it is centrifugally forced to acircumferential outlet. The magnetic field is perpendicular to theradius of the chamber, and its axis of rotation is parallel to thedirection of the field. It is in this manner that the expenditure ofkinetic energy is in the direction of normal flow toward the outlet.

The foregoing constitutes certain objects and advantages of the presentinvention others of which will become apparent from the study of thefollowing specification, taken together with the drawings, in which:

Figure 1 is a vertical sectional view partly in elevation of anelectromagnetic centrifugal pump;

Figure 2 is a horizontal sectional view partly in elevation, taken onthe line 2-2 of Figure 1; and

Figure 3 is a horizontal sectional view, taken on the line 33 of Figure1.

The pump is devised to move liquid metal through it by centrifugalforce. This is attained by causing the metal to enter at a central inletinto a flat disk-shaped chamber, at which place the metal begins towhirl as the result of the interaction between a magnetic field that isrotating in a circular path within the chamber and the radial electriccurrent induced in the liquid by the rotating magnetic field. As thewhirling velocity increases, the metal is thrown outwardly bycentrifugal force into an annular peripheral chamber from which themetal exits through an outlet passage at the periphery.

One embodiment of this invention is described below. Referring first toFigure 1, the pump generally indicated at is supported on a cylinder 12which rests upon a solid base. The top edge of the cylinder 12 is fixedinto an annular groove 16 in an annular plate 14 which is theundersurface of the pump. At the center of the annular 2,730,951Patented Jan. 17, 1956 plate 14 is a central inlet 18 which is formed bya collar 20 that extends above and below said plate 14 and is welded toit at 19. An inlet pipe 22 fits into the lower extension of collar 20 at24 and is welded at 25. Attached to the plate 14 by means of bolts 26 isan annular housing 28 which forms the lower portion of a peripheralannular chamber generally indicated at 30. The upper portion of saidchamber is enclosed in an annular housing 32 that is welded around thecircumference at 34 to the lower housing 28. An annular member 38 isattached to the upper housing 32 by means of bolts 36. Likewise, a coverplate 40 is secured to the annular member 38 by bolts 42. Referring toFigures 2 and 3, a tangential outlet 31 is located in the periphery ofthe annular chamber 30 which may be regarded as an enlarged portion of adiskshaped chamber 44 (Fig. 1).

Within the pump is the flat disk-shaped chamber 44 which is horizontallydisposed between the central inlet 18 and the annular peripheral chamber30. An annular core 46 with windings 48 connected by supply lines 49 toa source of alternating current (not shown), is positioned above thedisk-shaped chamber 44 and adjacent thereto between the central inlet 18and the annular peripheral chamber 30. The annular core 46 is welded at50 to an annular plate 52 which is attached to the cover plate 40 bymeans of bolts 54. Below the disk-shaped chamber 44 is an annulararmature 56 which is adjacent thereto between the central inlet 18 andthe annular peripheral chamber 38, and which is welded at 58 to anannular member 68 which is, in turn, welded at 62 to the annularundersurface plate 14. The disk-shaped chamber 44 is formed by upper andlower walls 64 and 66, respectively. of nonmagnetic and relativelyelectrically resistant material, such as an alloy of Ni, 15% Cr, and 5%Fe, commonly called Inconel. The upper wall 64 is disposed adjacent tothe annular core 46 and is welded at its pen'phery to an annularsupporting member 68 which is integrated with the annular member 38 bythe weld 70. The lower wall 66 is positioned adjacent to the annulararmature 56 and is welded at its periphery to an annular supportingmember 72. This lower wall 66 is centrally apertured at 74, and thecollar 20, having an inner diameter substantially corresponding to thediameter of the aperture 74, is welded to the lower wall to form thecentral inlet passage 18.

To prevent vibration at the center of the pump, the upper disk-shapedwall 64 is clamped in place between an anvil member "1'6 and a clampingmember 78 (Figs. 1 and 3). The anvil member 76, which is disposed in thecentral inlet 18, is held in place by means of a spider-like framecomprising four spokes 80 (Fig. 3), radiating outwardly from the lowerend of the anvil member 76 and a cylinder rim member 82 which rests on ashoulder 84 provided on the inner surface of collar 20. Positioneddirectly above the anvil member 76 is the clamping member 78 that isheld in place by means of a set-screw 86 (Figs. 1 and 2) which isscrewed into the cover plate 40. Pressure on the clamping member 78 isequally distributed by means of a ball 88 in a cavity 90 in the upperend of said clamping member. In order to ventilate the core 46 andwindings 48, the cover plate 48 is apertured at 92 and 94 (Figs. 1 and2). Leakage of liquid metal from the pump is prevented by annulargaskets 96 clamped between the member 38 and the housing 32 and betweenthe bottom plate 14 and the housing 28, respectively.

The laminated annular core 46 is constructed by rolling a singleelongated strip of silicon steel with mica insulation into a coil. Thewindings 48, indicated schematically in the drawing, are similar to thewindings of the stator of a conventional three-phase motor. However,they differ from conventional windings in the position of core slots 98into which the windings are placed (Figs. 1

3 and 2). Radial core slots 98 are cut into the side of the core 46which is adjacent to the chamber 44. The magnetic field is therebyinduced across the chamber in a direction parallel with the axis of theannular core.

The operation of the pump is as follows: To start the pump it isnecessary to prime it with liquid metal by methods conventional tocentrifugal pumps so as to fill the pump chamber 44 and to close theelectrical circuit to energize the magnet. As indicated by the flowarrows in the drawings, the liquid metal enters through inlet pipe 22.The interaction between the rotating magnetic field produced by windings48 and the radial electric currents in the liquid metal induced by themoving magnetic field whirls the liquid about chamber 44 tocentrifugally force it into the enlarged chamber 30 from which it exitsthrough the outlet 31 in the periphery.

While the above description presents a single embodiment of theinvention, it is obvious that other pumps embodying the principles ofthe invention may be devised. For example, the armature could beconstructed so as to rotate rather than remain fixed. Likewise, thelower walls could be made of magnetic material. Other modifications willbe immediately apparent.

What is claimed is:

1. An electromagnetic pump for electrically conductive fluids comprisinga pair of spaced substantially parallel walls forming a flatpartitionless chamber, an inlet in a wall disposed substantiallycentrallythereof, an enlarged annular chamber surrounding andcommunicating with the first chamber and having an outlet in the planeof the first chamber, and electromagnetic means for creating a magneticfield rotating about said inlet and across the first chamber in adirection parallel with the axis of the annular chamber, said meansincluding an annular laminated core coaxial with the inlet, said corebeing on one side of the first chamber and abutting one of said walls,radial slots extending throughout one end of the core, windings in theslots, and an annular laminated armature abutting the other wall anddisposed on the side of the chamber opposite the core.

2. An electromagnetic pump for electrically conductive fluids comprisinga pair of spaced parallel nonmagnetic walls forming a fiat circularpartitionless chamber, an inlet centrally disposed in one of the walls,an enlarged annular chamber of substantially round crosssection disposedabout the periphery of and communicating with the first chamber, anannular laminated core coaxial with the inlet, said core being fixed onone side of the first chamber and abutting one of the nonmagnetic walls,radial slots extending completely through the core on the side adjacentto said Wall, windings in the slots, an annular laminated armatureabutting the other wall in a fixed position and disposed on the side ofthe first chamber opposite the core, said elements creating a rotatingmagnetic field about the inlet and across the first chamber in adirection parallel with the axis of the annular chamber, and atangential outlet in the enlarged annular chamber disposed in the planeof the first chamber, whereby a fluid, upon entering the pump, is causedto whirl about the first chamber until centrifugally forced into theenlarged annular chamber from which it exits through the outlet in theperiphery.

References Cited in the file of this patent UNITED STATES PATENTS2,652,778 Crever Sept. 22, 1953 2,658,452 Donelian Nov. 10, 1953 FOREIGNPATENTS 239,816 Switzerland Mar. 1, 1946 344,881 Great Britain Mar. 3,1931 528,091 Great Britain Oct. 22, 1940 543,214 Germany Feb. 3, 1932582,036 Great Britain Nov. 1, 1946 594,849 Great Britain Nov. 20, 1947888,532 France Sept. 6, 1943

1. AN ELECTROMAGNETIC PUMP FOR ELECTRICALLY CONDUCTIVE FLUIDS COMPRISINGA PAIR OF SPACED SUBSTANTIALLY PARALLEL WALLS FORMING A FLATPARTITIONLESS CHAMBER, AN INLET IN A WALL DISPOSED SUBSTANTIALLYCENTRALLY THEREOF, AN ENLARGE ANNULAR CHAMBER SURROUNDING ANDCOMMUNICATING WITH THE FIRST CHAMBER AND HAVING AN OUTLET IN THE PLANEOF THE FIRST CHAMBER, AND ELECTROMAGNETIC MEANS FOR CREATING A MAGNETICFIELD ROTATING ABOUT SAID INLET AND ACROSS THE FIRST CHAMBER IN ADIRECTION PARALLEL WITH THE AXIS OF THE ANNULAR CHAMBER, SAID MEANSINCLUDING AN ANNULAR LAMINATED CORE COAXIAL WITH THE INLET, SAID COREBEING ON ONE SIDE OF THE FIRST CHAMBER AND ABUTTING ONE OF SAID WALLS,RADIAL SLOTS EXTENDING THROUGHOUT ONE END OF THE CORE, WINDINGS IN THESLOTS, AND AN ANNULAR LIMINATED ORMATURE ABUTTING THE OTHER WALL ANDDISPOSED ON THE SIDE OF THE CHAMBER OPPOSITE THE CORE.